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3D printing in construction presents numerous advantages, such as geometric flexibility, potential cost and time savings, the incorporation of recycled and sustainable materials, and reduced waste, thereby reducing the construction sector's environmental impact. Despite these advantages, the widespread adoption of AM in construction faces hurdles, primarily due to the prohibitive costs of large-scale concrete printers — typically ranging from $180,000 to over $1 million — and technological constraints that impede research and development efforts within the construction sector. To address these challenges, our study focuses on designing, developing, calibrating and evaluating an affordable lab-scale 3D printer specifically tailored for cement-based materials, aiming to lower the entry barrier for AM research in construction. This paper presents a proof-of-concept for a simple, yet functional printing technology that meet the requirements for research studies. The study details the development process, from the conceptual design to the calibration of printing parameters. The development process included the assessment of preliminary extrusion system designs integrated with the motion systems of a fused deposition modeling 3D printer. Subsequently, material studies were carried out to determine optimal material mix compositions and ratios. A comprehensive calibration of printing parameters using statistical analysis was proposed to ensure consistent and quality printing. The printability and applicability of the proposed small-scale 3D printer were assessed by printing samples and testing their thermal properties. Cost analysis showed that the proposed 3D printer, costing $273, offers benefits compared to existing market alternatives. The study illustrates the potential of small-scale 3D printers to facilitate construction research and practices, thereby promoting the development of sustainable construction methods.

The built environment sector is responsible for almost one-third of the world's final energy consumption. Hence, seeking plausible solutions to minimise building energy demands and mitigate adverse environmental impacts is necessary. Artificial intelligence (AI) techniques such as machine and deep learning have been increasingly and successfully applied to develop solutions for the built environment. This review provided a critical summary of the existing literature on the machine and deep learning methods for the built environment over the past decade, with special reference to holistic approaches. Different AI-based techniques employed to resolve interconnected problems related to heating, ventilation and air conditioning (HVAC) systems and enhance building performances were reviewed, including energy forecasting and management, indoor air quality and occupancy comfort/satisfaction prediction, occupancy detection and recognition, and fault detection and diagnosis. The present study explored existing AI-based techniques focusing on the framework, methodology, and performance. The literature highlighted that selecting the most suitable machine learning and deep learning model for solving a problem could be challenging. The recent explosive growth experienced by the research area has led to hundreds of machine learning algorithms being applied to building performance-related studies. The literature showed that existing research studies considered a wide range of scope/scales (from an HVAC component to urban areas) and time scales (minute to year). This makes it difficult to find an optimal algorithm for a specific task or case. The studies also employed a wide range of evaluation metrics, adding to the challenge. Further developments and more specific guidelines are required for the built environment field to encourage best practices in evaluating and selecting models. The literature also showed that while machine and deep learning had been successfully applied in building energy efficiency research, most of the studies are still at the experimental or testing stage, and there are limited studies which implemented machine and deep learning strategies in actual buildings and conducted the post-occupancy evaluation.

The increased adoption of photovoltaic (PV) systems for global decarbonisation necessitates addressing the gap in reduced panel efficiency due to overheating. This issue is especially prominent in countries with extremely hot and humid climates where PV utilisation is hindered by declining panel output. A systematic review of PV cooling techniques suggests passive systems are more economical, sustainable, and easier to implement than active systems, despite possessing a lower cooling potential. Air-based systems were deemed the most viable for the UAE’s climate, considering both performance and cost. Based on these findings, two individual improvements for air-based cooling systems were combined in an attempt to achieve greater cooling: a segmented multiangular aluminium fin heatsink developed from previous works. Various perforation patterns were simulated on the chosen heatsink using CFD software to determine the most optimal arrangement. The original and optimised models were both tested under real-life conditions in Dubai, United Arab Emirates, revealing similar cooling potential between the two. The results of this study indicate that the PV cell temperature can be decreased by up to 10 °C with the placement of an aluminium fin heatsink, which corresponds to an approximate efficiency increase of 5%.

An ever-increasing challenge of global warming and climate change is the issue of overheating in buildings. Several studies have developed numerous passive strategies to lessen the effects of overheating and reduce cooling energy consumption. For instance, thermal mass stores the thermal energy, which locks the heat away and prevents overheating. However, this must be discharged daily to ensure it can be used to store heat again. This discharging of heat can be achieved by night ventilation. The purpose of this research is to investigate the use of thermal mass and night ventilation in different climate conditions in China to minimise overheating in buildings under future climate conditions in 2050s and 2080s with four different greenhouse gas (GHG) emission scenarios. An office space model was employed to run full-year dynamic building simulations using Energyplus to simulate each thermal mass configuration in five cities (Guangzhou, Kunming, Shanghai, Beijing and Harbin) across China with varying climatic conditions. The study enabled the thermal mass configuration to be optimised for each specific climate and with the integrated night ventilation. The results highlighted night ventilation's vital role in decreasing overheating. The impact of night ventilation was found to reduce overheating hours by up to 60%. The method and results presented in this research can provide means for formulating strategies to combat overheating and to be incorporated into the regulations of buildings in China.

The built environment sector is responsible for a significant proportion of the final global energy consumption [...]

Natural ventilation is an energy-efficient way to provide fresh air and enhance indoor comfort levels. The wind-driven natural ventilation in courtyards has been investigated by many researchers, particularly the influence of the spatial configuration and environmental parameters on the ventilation and thermal comfort performance. However, previous research has mainly focused on the courtyard region instead of the indoor spaces surrounding it. Additionally, as a microclimate regulator, courtyards are rarely assessed in terms of the impact of vegetation, including its impact on energy consumption and thermal comfort. Evapotranspiration from vegetation can help lower air temperature in the surrounding environment and, therefore, its influence on the ventilation and thermal comfort in buildings with courtyards should be evaluated. The present study investigates the impact of vegetation on the aero-thermal comfort conditions in a courtyard and surrounding buildings in hot climates. Computational fluid dynamics was employed to evaluate the aero-thermal comfort conditions of the courtyard and surrounding buildings with different configurations of vegetation. The modeling was validated using previous works’ experimental data, and good agreement was observed. Thermal comfort indices were used to assess thermal performance. The study also evaluated the cover, height and planting area of vegetation in the courtyard. The results of this study can help develop tools that can assist the addition of vegetation in courtyards to maximize their effects. Future works will focus on looking at the influence of the strategies on different designs and layouts of courtyards.

To host the 2022 FIFA World Cup, Qatar is facing the greatest challenge in balancing the energy consumptions for cooling the stadiums and the thermal comfort for both players and spectators. Previous studies have not considered using a combined configuration of air curtain and roof cooling supply slot in stadiums to prevent the infiltration of outside hot air and reduce the cooling system’s energy consumption. This paper presents a Computational Fluid Dynamics (CFD) study of thermal and wind modeling around a baseline stadium and simulates the cooling scenarios of air curtains and roof cooling along with the energy consumption estimations for the World Cup matches using Building Energy Simulation (BES). Sensitivity analysis of different supply speeds and supply temperatures of air curtain gates and roof cooling was carried out, and the results showed that scenario six, which provides supply air of 25 m/s and 20 m/s at the roof and air curtain gates with a supply temperature of 10 °C, demonstrates optimal thermal performances on both the spectator tiers and the pitch. Compared with the baseline stadium performance, the average reductions in temperature on the pitch and spectator tiers under scenario six could reach 15 °C and 14.6 °C. The reductions in the Predicted Percentage of Dissatisfied values for the upper and lower tiers as well as the pitch were 63%, 74%, and 78%. In terms of the estimated energy consumptions, scenario six would consume electric energy per match at a rate of 25.5 MWh compared with 22.8 MWh for one of the stadiums in the 2010 South Africa World Cup and 42.0 MWh for the 2006 Germany World Cup. Future research is recommended to explore the influence of supply angle on air curtain gates and roof cooling supply slots’ performances.

The data presented in this article were the basis for the study reported in the research articles entitled “Evaluation of a two-sided windcatcher integrated with wing wall (as a new design) and comparison with a conventional windcatcher” (P. Nejat, J.K. Calautit, M.Z.A. Majid, B.R. Hughes, I. Zeynali, F. Jomehzadeh, 2016) [1] which presents the effect of wing wall on the air flow distribution under using the windcatchers as a natural ventilation equipment. Here, we detail the wind tunnel testing and numerical set-up used for obtaining the data on ventilation rates and indoor airflow distribution inside a test room with a two-sided windcatcher and wing wall. Three models were integrated with wing wall angled at 30°, 45° and 60° and another windcatcher was a conventional two-sided device. The computer-aided design (CAD) three-dimensional geometries which were produced using Solid Edge modeler are also included in the data article.

This article presents the datasets which were the results of the study explained in the research paper ‘Anti-short-circuit device: a new solution for short-circuiting in windcatcher and improvement of natural ventilation performance’ (P. Nejat, J.K. Calautit, M.Z. Abd. Majid, B.R. Hughes, F. Jomehzadeh, 2016) [1] which introduces a new technique to reduce or prevent short-circuiting in a two-sided windcatcher and also lowers the indoor CO2 concentration and improve the ventilation distribution. Here, we provide details of the numerical modeling set-up and data collection method to facilitate reproducibility. The datasets includes indoor airflow, ventilation rates and CO2 concentration data at several points in the flow field. The CAD geometry of the windcatcher models are also included.

The data presented in this article were the basis for the study reported in the research articles entitled ‘A validated design methodology for a closed loop subsonic wind tunnel’ (Calautit et al., 2014) [1], which presented a systematic investigation into the design, simulation and analysis of flow parameters in a wind tunnel using Computational Fluid Dynamics (CFD). The authors evaluated the accuracy of replicating the flow characteristics for which the wind tunnel was designed using numerical simulation. Here, we detail the numerical and experimental set-up for the analysis of the closed-loop subsonic wind tunnel with an empty test section. Keywords: Aerodynamics, Computational modelling, Flow quality, Wind engineering, Wind tunnel

This paper reviewed related research works and developments on the traditional architectural element “mashrabiya” focusing on its history, design and structure, typology, and functions in hot climates. Moreover, the paper assessed the effect of the traditional mashrabiya on the indoor thermal environment and thermal comfort in a selected case study building. For this purpose, two similar rooms were investigated in a selected historic building with abundant mashrabiyas located in the Makkah Region, specifically in Old Jeddah, Saudi Arabia. The field tests were conducted during a typical hot summer month with two different configurations. The study demonstrated that opening the mashrabiya allowed more airflow into the room during the day and reduced the indoor temperature by up to 2.4 °C as compared to the closed mashrabiya. Besides, the building envelope played an important role in preventing the high fluctuation of the indoor air temperature, where the fluctuation of the rooms air temperature ranged between 2.1 °C and 4.2 °C compared to the outdoor temperature which recorded a fluctuation between 9.4 °C and 16 °C. The data presented here can be used for the future development of the mashrabiya concept and the potential incorporation with passive cooling methods to improve its design according to the requirements of modern buildings in hot climates. Moreover, further studies and tests on mashrabiyas under different climatic conditions are required. Also, the different strategies or materials can be incorporated with mashrabiyas in order to improve its thermal performance.

Many high-rise buildings have semi-enclosed landscaped spaces, which act as design elements to improve the social and environmental aspects of the building. Designs such as skygardens are open to outdoor airflow and allow occupants to observe the city skyline from a height. Due to their often high location, they are subjected to strong wind speeds and extreme environmental conditions. The current study investigates the effects of three common wind buffers (railing, hedges, and trees) located at a height of 92 m on the performance of a skygarden, in terms of occupants’ wind comfort. Computational fluid dynamics (CFD) simulations were carried out using the realisable k-epsilon method, where the vegetation was modelled as a porous zone with cooling capacity. The computational modelling of the high-rise building and vegetation were validated using previous works. The quality class (QC) of the Lawson comfort criteria was used for the evaluation of the wind comfort across the skygarden. The results indicate that, although the three wind buffers offer varying levels of wind reduction in the skygarden, the overall wind conditions generated are suitable for occupancy. Furthermore, vegetation is also able to offer slight temperature reductions in its wake. The right combination and dimension of these elements can greatly assist in generating aero-thermal comfort across skygardens.

The twentieth-century development of Mexicanidad underwent a series of treatments that changed how selfhood in Mexico was problematized and understood. Octavio Paz’s claim that Mexicanidad faced historical and philosophical obstacles in its development, such as the problem of solitude, allowed him to go beyond the accounts of Mexicanidad provided by Justo Sierra, José Vasconcelos, and Samuel Ramos. Paz’s account of Mexicanidad sought an explicit connection between the Mexican experience of solitude and the universal human experience of solitude. This paper demonstrates how Paz’s revised account addresses these and other problems in twentieth-century Latin American quests for national identity.

The data presented in this article were the basis for the study reported in the research articles entitled ‘Climate responsive behaviour heat pipe technology for enhanced passive airside cooling’ by Chaudhry and Hughes [10] which presents the passive airside cooling capability of heat pipes in response to gradually varying external temperatures and related to the research article “CFD and wind tunnel study of the performance of a uni-directional wind catcher with heat transfer devices” by Calautit and Hughes [1] which compares the ventilation performance of a standard roof mounted wind catcher and wind catcher incorporating the heat pipe technology. Here, we detail the wind tunnel test set-up and inflow conditions and the methodologies for the transient heat pipe experiment and analysis of the integration of heat pipes within the control domain of a wind catcher design.

A detailed Computational Fluid Dynamics (CFD) and experimental investigation into characterizing the fluid flow and thermal profiles in a wind tunnel was carried out, highlighting the effect of progressive heating on the non-uniformity flow profile of air. Using controllable electrical heating elements, the operating temperatures in the test-section were gradually increased in order to determine its influence on the subsequent velocity and thermal profiles found inside the test-section. The numerical study was carried out using CFD FLUENT code, alongside validating the experimental results. Good correlation was observed as the comparison yielded a mean error of 6.4% for the air velocity parameter and 2.3% for the air temperature parameter between the two techniques. The good correlation established between the numerically predicted and experimentally tested results identified broad scope for using the advanced computational capabilities of CFD applicable to the thermal modeling of wind tunnels. For a constant temperature process, the non-uniformity and turbulence intensity in the test section was 0.9% and 0.5%, which is under the recommended guidelines for wind tunnels. The findings revealed that the increase in temperature from 20 °C to 50 °C reduced the velocity by 15.2% inside the test section.

Mechanical Heating Ventilation and Air-Conditioning (HVAC) systems account for 60% of the total energy consumption of buildings. As a sector, buildings contributes about 40% of the total global energy demand. By using passive technology coupled with natural ventilation from wind towers, significant amounts of energy can be saved, reducing the emissions of greenhouse gases. In this study, the development of Computational Fluid Dynamics (CFD) analysis in aiding the development of wind towers was explored. Initial concepts of simple wind tower mechanics to detailed design of wind towers which integrate modifications specifically to improve the efficiency of wind towers were detailed. From this, using CFD analysis, heat transfer devices were integrated into a wind tower to provide cooling for incoming air, thus negating the reliance on mechanical HVAC systems. A commercial CFD code Fluent was used in this study to simulate the airflow inside the wind tower model with the heat transfer devices. Scaled wind tunnel testing was used to validate the computational model. The airflow supply velocity was measured and compared with the numerical results and good correlation was observed. Additionally, the spacing between the heat transfer devices was varied to optimise the performance. The technology presented here is subject to a patent application (PCT/GB2014/052263).

A numerical investigation was carried out to determine the impact of structural morphology on the power generation capacity of building-integrated wind turbines. The performance of the turbines was analysed using the specifications of the Bahrain Trade Centre which was taken as the benchmark model, the results of which were compared against triangular, square and circular cross-sections of the same building. The three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9 % for the benchmark model. The square and circular configurations however determined greater capacity factors of 12.2 % and 19.9 %, recording an estimated power production capability of 26.9 kW and 35.1 kW and confirming the largest extraction of the incoming wind stream. The optimum cross-sectional configuration for installing wind turbines in high-rise buildings was the circular orientation as the average wind speed at the wind turbines was accelerated by 0.3 m/s resulting in an overall augmentation of 5 %. The results from this study therefore highlighted that circular building morphology is the most viable building orientation, particularly suited to regions with a dominant prevailing wind direction.

High-rise buildings are known to be highly energy intensive, adding stress on already stressed resources. Alternatively, designers are looking at passive strategies and investing in architectural elements, such as sky gardens, which could improve the performance of buildings. Sky gardens are green areas located in a building which are exposed to the outdoors. They could provide multifaceted improvements in buildings by introducing environmental benefits to occupants and altering microclimate. This study aims to determine the wind comfort and thermal condition in sky gardens in high-rise buildings using numerical modelling. Different geometrical configurations of sky gardens were simulated and analysed. Based on the initial results, the study reveals that sky gardens can generate high wind velocities of the order ~10 m/s when located on a high-rise building. The addition of features such as trees and other architectural elements, which can act as a buffer, can help attenuate the high wind speeds and creating habitable spaces. The reduction varies 50%–80%, depending on the location and spatial domain of the sky garden. Furthermore, the study also investigated the reduction in air temperature due to the addition of trees, which can further reduce temperature in hot weather.

Generally, two-third of a building’s energy is consumed by heating, ventilation and air-conditioning systems. One green alternative for conventional air conditioner systems is the implementation of passive cooling. Wing walls and windcatchers are two prominent passive cooling techniques which use wind as a renewable resource for cooling. However, in low wind speed regions and climates, the utilization of natural ventilation systems is accompanied by serious uncertainties. The performance of ventilation systems can be potentially enhanced by integrating windcatchers with wing walls. Since previous studies have not considered this integration, in the first part of this research the effect of this integration on the ventilation performance was assessed and the optimum angle was revealed. However, there is still gap of this combination; thus, in the second part, the impact of wing wall length on the indoor air quality factors was evaluated. This research implemented a Computational Fluid Dynamics (CFD) method to address the gap. The CFD simulation was successfully validated with experimental data from wind tunnel tests related to the previous part. Ten different lengths from 10 cm to 100 cm were analyzed and it was found that the increase in wing wall length leads to a gradual reduction in ventilation performance. Hence, the length does not have a considerable influence on the indoor air quality factors. However, the best performance was seen in 10 cm, that could provide 0.8 m/s for supply air velocity, 790 L/s for air flow rate, 39.5 1/h for air change rate, 107 s for mean age of air and 92% for air change effectiveness.

Global demand for energy continues to increase rapidly, due to economic and population growth, especially for increasing market economies. These lead to challenges and worries about energy security that can increase as more users need more energy resources. Also, higher consumption of fossil fuels leads to more greenhouse gas emissions, which contribute to global warming. Moreover, there are still more people without access to electricity. Several studies have reported that one of the rapidly developing source of power is wind energy and with declining costs due to technology and manufacturing advancements and concerns over energy security and environmental issues, the trend is predicted to continue. As a result, tools and methods to simulate and optimize wind energy technologies must also continue to advance. This paper reviews the most recently published works in Computational Fluid Dynamic (CFD) simulations of micro to small wind turbines, building integrated with wind turbines, and wind turbines installed in wind farms. In addition, the existing limitations and complications included with the wind energy system modelling were examined and issues that needs further work are highlighted. This study investigated the current development of CFD modelling of wind energy systems. Studies on aerodynamic interaction among the atmospheric boundary layer or wind farm terrain and the turbine rotor and their wakes were investigated. Furthermore, CFD combined with other tools such as blade element momentum were examined.

The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment.

For centuries, dome roofs were used in traditional houses in hot regions such as the Middle East and Mediterranean basin due to its thermal advantages, structural benefits and availability of construction materials. This article presents the computational modelling of the wind- and buoyancy-induced ventilation in a geodesic dome building in a hot climate. The airflow and temperature distributions and ventilation flow rates were predicted using Computational Fluid Dynamics (CFD). The three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations were solved using the CFD tool ANSYS FLUENT15. The standard k-epsilon was used as turbulence model. The modelling was verified using grid sensitivity and flux balance analysis. In order to validate the modelling method used in the current study, additional simulation of a similar domed-roof building was conducted for comparison. For wind-induced ventilation, the dome building was modelled with upper roof vents. For buoyancy-induced ventilation, the geometry was modelled with roof vents and also with two windows open in the lower level. The results showed that using the upper roof openings as a natural ventilation strategy during winter periods is advantageous and could reduce the indoor temperature and also introduce fresh air. The results also revealed that natural ventilation using roof vents cannot satisfy thermal requirements during hot summer periods and complementary cooling solutions should be considered. The analysis showed that buoyancy-induced ventilation model can still generate air movement inside the building during periods with no or very low wind.